Sporadic childhood Burkitt lymphoma incidence in the United States during 1992-2005

Xanthogranulomatous Appendicitis Mimicking Residual Burkitt's Lymphoma After Chemotherapy

The case of a 23-year-old female treated with aggressive high-dose therapy for Burkitt's lymphoma is reported. A positron emission tomography and computed tomography scan after completion of chemotherapy revealed a residual hypermetabolic lesion in the right pelvic cavity. A pelvic magnetic resonance imaging scan showed circumferential wall thickening at the tip of the appendix. A laparoscopic exploration and appendectomy were performed, and a pathologic examination of the resected appendix revealed xanthogranulomatous appendicitis. This is a rare case of a xanthogranulomatous appendicitis mimicking remnant Burkitt's lymphoma after completion of chemotherapy.

Pediatric lymphomas and histiocytic disorders of childhood

Although there have been dramatic improvements in the treatment of children with non-hodgkin lymphoma, hodgkin lymphoma and histiocytic disorders over the past 3 decades, many still relapse or are refractory to primary therapy. In addition, late effects such as 2nd malignancies, cardiomyopathy and infertility remain a major concern. Thus, this review focuses on the current state of the science and, in particular, novel treatment strategies that are aimed at improving outcomes for all pediatric patients with lymphoma and histiocytic disorders while reducing treatment related morbidity.

Prognostic Value and Clinical Impact of (18)FDG-PET in the Management of Children with Burkitt Lymphoma after Induction Chemotherapy

OBJECTIVE

Burkitt lymphoma (BL) is a rare and aggressive form of B-cell lymphoma that is curable using intensive chemotherapy. Obtaining a complete response (CR) at the end of induction chemotherapy is a major prognostic factor. This study retrospectively evaluates the potential impact of (18)FDG-PET in the management of children with BL after induction chemotherapy, and the prognostic performance of the Deauville criteria.

METHODS

Nineteen children with BL treated according to the French LMB2001 protocol between 2005 and 2012 were included. (18)FDG-PET and conventional imaging (CI) were performed after induction chemotherapy to confirm CR. (18)FDG-PET was interpreted according to Deauville criteria with follow-up and/or histology as the gold standard.

RESULTS

(18)FDG-PET was negative in 15 cases, in agreement with CI in 9/15 cases. The six discordant cases confirmed to be negative by histology, were considered as true negative for (18)FDG-PET. Negative predictive value (NPV) of CI and (18)FDG-PET were 73 and 93%, respectively. The 5-year progression-free survival (PFS) was significantly higher in patients with negative (18)FDG-PET than those with positive (18)FDG-PET (p = 0.011).

CONCLUSION

(18)FDG-PET interpreted using Deauville criteria can help confirm CR at the end of induction chemotherapy, with a prognostic impact on 5-year PFS. Its high NPV could limit the use of residual mass biopsy. Given the small size of our population, these results need to be confirmed by future prospective studies on a larger population.

Quantitative analysis of CDKN2A methylation, mRNA, and p16(INK4a) protein expression in children and adolescents with Burkitt lymphoma: biological and clinical implications

CDKN2A is a tumor suppressor gene critical in the cell cycle regulation. Little is known regarding the role of CDKN2A methylation in the pathogenesis of Burkitt lymphoma (BL). CDKN2A methylation was investigated using pyrosequencing in 51 tumor samples. p16(INK4a) mRNA and protein levels were measured using real-time PCR and immunohistochemistry, respectively. CDKN2A methylation was detectable in 72% cases. Nuclear expression of p16(INK4a) was not detected in 41% cases. There was an association between methylation and absence of CDKN2A mRNA (P=0.003). In conclusion, CDKN2A methylation occurs at a high frequency suggesting a role in BL pathogenesis and potential therapeutic implications.

Biomarkers in childhood non-Hodgkin's lymphomas

Pediatric non-Hodgkin's lymphomas (NHLs) are a heterogeneous group of malignancies with distinct clinical, pathological, immunological and genetic characteristics. More than 90% of pediatric NHLs belong to one of three major histological subtypes: mature B-cell neoplasms, lymphoblastic lymphomas and anaplastic large-cell lymphomas. The recognition that different subtypes require different treatment regimens resulted in therapeutic strategies leading to over 80% of patients being cured. On the other hand, patients with resistant or relapsed disease have a poor prognosis. Prognostic biomarkers have not yet been identified for all pediatric NHLs and, although some are very important for diagnosis and prognosis, others may be of questionable value. Discovery of new biomarkers suitable for clinical application may aid the diagnosis and classification of lymphomas, which should, in turn, lead to better patient stratification. Consequent development of new treatment and follow-up approaches should lead to more efficient and less toxic treatment in children with NHL.

Burkitt Lymphoma: beyond discoveries

First described in 1958 in Uganda, Burkitt lymphoma (BL) attracted interest worldwide following reports of its uneven geographic distribution and rapidly fatal clinical course. Both suggested infectious etiology and curability. Seminal discoveries followed in quick succession. Viral etiology - due to Epstein-Barr virus (EBV) - was confirmed. Chromosomal translocations, involving cellular MYC, a protooncogene, were discovered, shown to be a hallmark of BL, and central to the genetic basis of cancer. Cure of BL using combination chemotherapy was demonstrated. Unfortunately, civil disturbance in Africa disrupted BL research and blunted its impact on education and oncology care in Africa. Important questions went unanswered. The risk of BL due to malaria or EBV was not quantified. Efforts to answer whether BL could be prevented - by preventing malaria or early EBV infection - were abandoned. The mechanism of malaria in BL is unknown. In Africa, BL remains mostly fatal and diagnosis is still made clinically. Unprecedented advances in molecular, genomics and proteomic technologies, promising to unlock mysteries of cancers, have re-awakened interest in BL. With return of stability to Africa, the unanswered questions about BL are re-attracting global interest. This interest now includes exploiting the knowledge gained about genetics, proteomics, and bioinformatics to enable the development of targeted less toxic treatment for BL; and simpler methods to diagnose BL with high accuracy and sensitivity. The articles in the Burkitt Lymphoma (BL): Beyond Discoveries in Infectious Agents and Cancer highlight BL as priority. Authors explore etiology, pathology, pathogenesis of BL, and whether knowledge gained in the studies of BL can catalyze sustainable cancer services in one of the world's poorest served regions.

Burkitt lymphoma risk in U.S. solid organ transplant recipients

Case reports of Burkitt lymphoma (BL) in transplant recipients suggest that the risk is markedly elevated. Therefore, we investigated the incidence of BL in 203,557 solid organ recipients in the U.S. Transplant Cancer Match Study (1987-2009) and compared it with the general population using standardized incidence ratios. We also assessed associations with demographic and clinical characteristics, and treatments used to induce therapeutic immunosuppression. BL incidence was 10.8 per 100,000 person-years, representing 23-fold (95% confidence interval (CI) 19-28) greater risk than in the general population, and it peaked 3-8 years after the time of transplantation. In adjusted analyses, BL incidence was higher in recipients transplanted when <18 vs. ≥35 years (incidence rate ratio [IRR] 3.49, 95% CI 2.08-5.68) and in those transplanted with a liver (IRR 2.91, 95% CI 1.68-5.09) or heart (IRR 2.39, 95% CI 1.30-4.31) compared with kidney. BL incidence was lower in females than males (IRR 0.45, 95% CI 0.28-0.71), in blacks than whites (IRR 0.33, 95% CI 0.12-0.74), in those with a baseline Epstein-Barr virus (EBV)-seropositive versus EBV-seronegative status (IRR 0.34, 95% CI 0.13-0.93), and in those treated with azathioprine (IRR 0.56, 95% CI 0.34-0.89) or corticosteroids (IRR 0.48, 95% CI 0.29-0.82). Tumors were EBV-positive in 69% of 32 cases with results. EBV positivity was 90% in those aged <18 years and 59% in those aged 18+ years. In conclusion, BL risk is markedly elevated in transplant recipients, and it is associated with certain demographic and clinical features. EBV was positive in most but not all BL cases with results.

Relationship between non-Hodgkin's lymphoma and blood levels of Epstein-Barr virus in children in north-western Tanzania: a case control study

Background

Non-Hodgkin’s Lymphomas (NHL) are common in African children, with endemic Burkitt’s lymphoma (BL) being the most common subtype. While the role of Epstein-Barr Virus (EBV) in endemic BL is known, no data are available about clinical presentations of NHL subtypes and their relationship to Human Immunodeficiency Virus (HIV) infection and Epstein Barr Virus (EBV) load in peripheral blood of children in north-western, Tanzania.

Methods

A matched case control study of NHL subtypes was performed in children under 15 years of age and their respective controls admitted to Bugando Medical Centre, Sengerema and Shirati district designated hospitals in north-western, Tanzania, between September 2010 and April 2011. Peripheral blood samples were collected on Whatman 903 filter papers and EBV DNA levels were estimated by multiplex real-time PCR. Clinical and laboratory data were collected using a structured data collection tool and analysed using chi-square, Fisher and Wilcoxon rank sum tests where appropriate. The association between NHL and detection of EBV in peripheral blood was assessed using conditional logistic regression model and presented as odds ratios (OR) and 95% confidence intervals (CI).

Results

A total of 35 NHL cases and 70 controls matched for age and sex were enrolled. Of NHLs, 32 had BL with equal distribution between jaw and abdominal tumour, 2 had large B cell lymphoma (DLBCL) and 1 had NHL-not otherwise specified (NHL-NOS). Central nervous system (CNS) presentation occurred only in 1 BL patient; 19 NHLs had stage I and II of disease. Only 1 NHL was found to be HIV-seropositive. Twenty-one of 35 (60%) NHL and 21 of 70 (30%) controls had detectable EBV in peripheral blood (OR = 4.77, 95% CI 1.71 – 13.33, p = 0.003). In addition, levels of EBV in blood were significantly higher in NHL cases than in controls (p = 0.024).

Conclusions

BL is the most common childhood NHL subtype in north-western Tanzania. NHLs are not associated with HIV infection, but are strongly associated with EBV load in peripheral blood. The findings suggest that high levels of EBV in blood might have diagnostic and prognostic relevance in African children.

Incidence and trends in Burkitt lymphoma in northern Tanzania from 2000 to 2009

INTRODUCTION

Burkitt lymphoma (BL) is endemic in parts of Tanzania, but there is scant country or region level data about burden and trends of BL in Tanzania over the past three decades. Here, we update baseline epidemiology of BL in northern Tanzania using recent data.

PROCEDURE

Data for childhood BL diagnosed at six hospitals in Mara and Mwanza regions in northern Tanzania during 2000-2009 were compiled. Age, sex, and regional patterns were analyzed. Crude incidence rates of BL were calculated by sex, anatomic site, geographical region, and calendar year.

RESULTS

Among 944 cases, 549 (58%) were male (male/female case ratio 1.4:1). Among those with known anatomic site (92%), facial only tumors represented a large proportion of tumors in boys than girls (50% vs. 36%, P < 0.002). Tumors occurred at a younger mean age in boys than girls (6.8 years vs. 7.6 years, P < 0.01). Crude BL incidence was 4.2 per 100,000, but varied by region (3.0 in Mwanza vs. 6.8 in Mara, P = 0.01), by district (1.4-22), by gender (5.0 in boys vs. 4.0 in girls), and by age group (2.0 in 0-4, 7.8 in 5-9, and 3.1 in 10-15 years). BL incidence peaked in 2001 and decreased gradually thereafter.

CONCLUSIONS

Our results indicate that male sex, young age, and geographical characteristics are risk factors for BL in Tanzania. BL incidence declined with calendar year, but the significance of this finding is uncertain. Well-designed epidemiological studies of BL in Tanzania may shed light on environmental characteristics underlying these patterns.

Gastric Burkitt's lymphoma in a child: A rare case

Burkitt's lymphoma (BL) is a high-grade lymphoma which represents 8-10% of all tumors in individuals younger than 15 years old. It may occur as an abdominal tumor, which in rare cases may include gastric mucosa, although in most cases, the tumor is located in the ileum or cecum. Primary gastric lymphoma constitutes as low as 1.48% of all gastric cancers in children. In this study, we described a case of gastric BL in a 4-year-old child, presenting discontinuous abdominal pain, weight loss, constipation and irritability. Despite its rarity in children, this tumor should be treated aggressively and long-term survival has been reported.

Sporadic Burkitt lymphomas of children and adolescents in Chinese: a clinicopathological study of 43 cases

Background

To investigate the clinical and pathologic features as well as the MYC translocations of childhood Burkitt lymphoma (BL) from China.

Methods

Fourty-three cases of childhood BL were retrospectively investigated in morphology, immunophenotype, genotype, treatments and survival analysis.

Results

Clinically, there was a marked male predominance in sex distribution (M: F = 9.75:1); abdomen was the most frequent extranodal sites of involvement (46.5 %), followed by jaws and facial bones (16.3 %). Two third of the patients were in stageI ~ II. Morphologically, 69.76 % of the cases showed classical histologic features, while 30.24 % of them showed greater nuclear pleomorphism in size and shape. Five cases (11.6 %) were positive for EBER1/2. Thirty-one of the 40 cases (77.5 %) had the aberration of IGH/MYC translocation while 7 (17.5 %) had non-IGH/MYC translocation. Thirty patients (69.7 %) received operation and/or chemotherapy while 13 patients (30.3 %) received no treatment. Twenty-seven patients (62.8 %) died of the tumor, 16 alive, with the average survival time 4.9 and 48.7 months respectively. High IPI, advanced clinical stage, increased serum level of LDH and no chemotherapy received as well as tumor size ≥10 cm were related to the lower survival rates of the tumor.

Conclusions

Several differences were showed in this group of BL, including a much higher ratio of male patients, more cases in stageII, clinically inconsistent treatment and a very poor outcome.

Virtual slides

The virtual slide(s) for this article can be found here http://www.diagnosticpathology.diagnomx.eu/vs/1552295877710135

Pediatric, elderly, and emerging adult-onset peaks in Burkitt's lymphoma incidence diagnosed in four continents, excluding Africa

Burkitt's lymphoma (BL) in the general population and immunosuppressed persons with AIDS in the United States was characterized by three age-specific incidence peaks near 10, 40, and 70 years. We hypothesized that BL from different geographical areas may exhibit pediatric, adult, and elderly age incidence peaks. We investigated this hypothesis using data on 3,403 cases obtained from the International Agency for Research on Cancer (1963-2002). Data from Africa were sparse or incomplete, and thus were excluded. Age-standardized rates (ASRs) and age-specific incidence rates were calculated, supplemented with the calculations performed using age-period-cohort (APC) models. The ASR rose 5.3% (95% confidence interval [CI], 5.0-5.6) per year in males and 4.6% (95% CI, 4.5-4.8) in females. The ASR increased gradually in children, steeply in adults and most rapidly in the elderly both in males and in females. Overall, BL male/female ASR ratio was 2.5, but it declined from 3.1 (95% CI, 3.0-3.3) for pediatric BL to 2.3 (95% CI, 2.2-2.4) for adult BL and 1.5 (95% CI, 1.4-1.6) for elderly BL. Age-specific incidence peaks occurred near 10 and 70 years in all regions and periods. A peak near 40 years of age emerged in the mid-1990s, particularly in men. Findings using APC models confirmed those based on the standard analyses. Our findings, based on the international BL cases, support our hypothesis that BL is multimodal and that BL peaks at different ages may be clues to differences in the etiology and/or biology of BL at those ages.

Epidemiology of Burkitt's lymphoma in Northwest Province, Cameroon, 2003-2010

BACKGROUND

Burkitt's lymphoma (BL) is an aggressive non-Hodgkin's lymphoma endemic to regions of Africa. Cases are thought to be typically found in low-lying, humid regions where malaria is rife.

AIMS AND OBJECTIVES

To investigate the clinical characteristics of BL, its incidence and relationship with malarial incidence in Northwest (NW) Province, Cameroon.

METHODS

Data on BL were collected from the three tertiary referral centres for BL treatment in NW Province, Cameroon. Data on malaria were collected from the Delegation of Public Health in Bamenda, NW Province. Data were collected between March and May 2010.

RESULTS

471 cases of BL were identified. The St Jude's stage of patients at presentation was as follows: stage I, 14.4% (43/299); stage II, 8.4% (25/299); stage III, 69.9% (209/299); stage IV, 7.4% (22/299). The incidences of BL per 100,000 children <15 years of age from 2005 to 2009 were as follows: 2005, 3.01 (29); 2006, 2.02 (20); 2007, 2.45 (25); 2008, 2.38 (25); 2009, 3.06 (33). The average incidence in NW Province was 2.58. In the Ndop plain, Ngo-Ketunjia, the incidences of BL were as follows: 2005, 10.3 (10); 2006, 3.00 (3); 2007, 1.95 (2); 2008, 2.84 (3); 2009, 4.60 (5). The average incidence was 4.54/100,000 children <15 years of age. Statistical analysis demonstrated a sinusoidal distribution of malaria cases throughout the year (P<0.00), with a peak incidence on 10 April. Conversely, no sinusoidal distribution of BL cases was demonstrated throughout the year (P = 0.09).

CONCLUSION

No relationship was demonstrated between an acute malarial infection and BL. Significant clustering was found, with the low-lying Ndop plain of Ngo-Ketunjia having an incidence of BL nearly twice that elsewhere in the region. The study demonstrates that the incidence of BL in NW Province, Cameroon remains one of the highest documented in the world.

Burkitt's lymphoma

Burkitt's lymphoma is a highly aggressive B-cell non-Hodgkin lymphoma and is the fastest growing human tumour. The disease is associated with Epstein-Barr virus and was one of the first tumours shown to have a chromosomal translocation that activates an oncogene (c-MYC). Burkitt's lymphoma is the most common childhood cancer in areas where malaria is holoendemic. The incidence is very high in immunosuppressed patients in non-endemic areas, especially when associated with HIV infection. Outcome with intensive chemotherapy has improved and is now excellent in children, but the prognosis is poor in elderly adults. The success of intensive treatment relies on good supportive care. The therapy offered in oncology units in low-income countries is not as aggressive as in centres in high-income countries and outcomes are less successful. Adjuvant monoclonal antibody therapy with rituximab shows promise for improved outcomes and reduced toxic effects in the future.

Is birth weight associated with childhood lymphoma? A meta-analysis

Several risk factors have been identified for childhood lymphomas. The purpose of this meta-analysis was to synthesize current evidence regarding the association between birth weight with primarily the risk for non-Hodgkin lymphoma (NHL), given its similarity to acute lymphoblastic leukemia, Hodgkin lymphoma (HL) and any category of lymphoma. Two cohort (278,751 children) and seven case-control studies (2,660 cases and 69,274 controls) were included. Effects estimates regarding NHL, HL and any lymphoma were appropriately pooled using fixed or random effects model in two separate analyses: specifically, high was compared to normal or any birth weight. Similarly, low was compared to normal or any birth weight. No statistically significant association was found between high birth weight, as compared to normal birth weight, and risk for NHL plus Burkitt lymphoma (OR = 1.17, 95% CI = 0.76-1.80, random effects), HL (OR = 0.94, 95% CI = 0.64-1.38, fixed effects) or any plus Burkitt lymphoma (OR = 1.09, 95% CI = 0.76-1.56, fixed effects). A null association emerged when low was compared with normal birth weight for NHL plus Burkitt lymphoma (OR = 1.07, 95% CI = 0.71-1.62, random effects), HL (OR = 0.94, 95% CI = 0.54-1.65, fixed effects) or any plus Burkitt lymphoma (OR = 1.02, 95% CI = 0.79-1.33, fixed effects). Accordingly, no association was found when high or low birth weight was compared to any birth weight. Although current evidence suggests no association, birth weight might be a too crude indicator to reveal a genuine association of fetal growth with specific lymphoma categories; hence, there is an emerging need for use of more elaborate proxies, at least those accounting for gestational week.

Effect of ligand-activated estrogen receptor β on lymphoma growth in vitro and in vivo

Estrogen receptor β (ERβ) is expressed in immune cells and studies have suggested an antiproliferative function of ERβ. We detected ERβ expression in murine T- and human B-cell lymphoma cell lines and analyzed the effects of estradiol and selective ERβ agonists on lymphoma growth in culture and in vivo. Treating the cells with estradiol had minor effects on cell growth, whereas the selective ERβ agonists diarylpropionitrile (DPN) and KB9520 showed a strong antiproliferative effect. When grafting mice with murine T-cell lymphoma cells, male mice developed larger tumors compared with female mice, a difference that was abolished following ovariectomy, showing estrogen-dependent growth in vivo. To investigate whether lymphoma growth may be inhibited in vivo by ERβ agonist treatment, mice grafted with murine lymphoma cells were treated with DPN or KB9520. Both ERβ-selective agonists strongly inhibited lymphoma growth. The reduced tumor size seen following either DPN or KB9520 treatment was due to reduced proliferation and increased apoptosis. Our results show an ERβ ligand-dependent antiproliferative effect of lymphoma cells expressing endogenous ERβ and that lymphoma cell growth in vivo can efficiently be inhibited by ERβ agonists. This suggests that ERβ agonists may be useful in the treatment of lymphomas.

Burkitt lymphoma: pathogenesis and immune evasion

B-cell lymphomas arise at distinct stages of cellular development and maturation, potentially influencing antigen (Ag) presentation and T-cell recognition. Burkitt lymphoma (BL) is a highly malignant B-cell tumor associated with Epstein-Barr Virus (EBV) infection. Although BL can be effectively treated in adults and children, leading to high survival rates, its ability to mask itself from the immune system makes BL an intriguing disease to study. In this paper, we will provide an overview of BL and its association with EBV and the c-myc oncogene. The contributions of EBV and c-myc to B-cell transformation, proliferation, or attenuation of cellular network and immune recognition or evasion will be summarized. We will also discuss the various pathways by which BL escapes immune detection by inhibiting both HLA class I- and II-mediated Ag presentation to T cells. Finally, we will provide an overview of recent developments suggesting the existence of BL-associated inhibitory molecules that may block HLA class II-mediated Ag presentation to CD4+ T cells, facilitating immune escape of BL.

AIDS-related Burkitt lymphoma in the United States: what do age and CD4 lymphocyte patterns tell us about etiology and/or biology?

Trimodal or bimodal age-specific incidence rates for Burkitt lymphoma (BL) were observed in the United States general population, but the role of immunosuppression could not be excluded. Incidence rates, rate ratios, and 95% confidence intervals for BL and other non-Hodgkin lymphoma (NHL), by age and CD4 lymphocyte count categories, were estimated using Poisson regression models using data from the United States HIV/AIDS Cancer Match study (1980-2005). BL incidence was 22 cases per 100 000 person-years and 586 for non-BL NHL. Adjusted BL incidence rate ratio among males was 1.6× that among females and among non-Hispanic blacks, 0.4× that among non-Hispanic whites, but unrelated to HIV-transmission category. Non-BL NHL incidence increased from childhood to adulthood; in contrast, 2 age-specific incidence peaks during the pediatric and adult/geriatric years were observed for BL. Non-BL NHL incidence rose steadily with decreasing CD4 lymphocyte counts; in contrast, BL incidence was lowest among people with ≤ 50 CD4 lymphocytes/μL versus those with ≥ 250 CD4 lymphocytes/μL (incidence rate ratio 0.3 [95% confidence interval = 0.2-0.6]). The bimodal peaks for BL, in contrast to non-BL NHL, suggest effects of noncumulative risk factors at different ages. Underascertainment or biological reasons may account for BL deficit at low CD4 lymphocyte counts.

Trimodal age-specific incidence patterns for Burkitt lymphoma in the United States, 1973-2005

Burkitt lymphoma (BL) is a unique B-cell non-Hodgkin lymphoma with 3 established clinical-epidemiological variants: endemic, sporadic and AIDS-related BL. BL variants show characteristic dysregulation of MYC gene, but the causes of MYC dysregulation or BL arising at different ages are poorly understood. Therefore, we examined population-based BL incidence patterns in the United States to determine age-related risk. BL case and population data were obtained from the NCI's Surveillance, Epidemiology and End Results Databases (1973-2005). Standard cross-sectional age-standardized and age-specific incidence rates were stratified by sex and race and supplemented with age-period-cohort models. We analyzed 3,058 BL cases diagnosed during 1,160,300,297 person-years of observation. Age-standardized incidence rates rose 6.8% per year (95% CI 4.5-9.1) for males and 7.1% (95% CI 3.2-11.1) for females during the study period. The rate among males was 3.2 times that among females, and among Whites 1.3 times that among Blacks. Male-to-female incidence rate ratios did not differ by race, but were 4.2 for pediatric (0-19 years), 4.1 for adult (20-59 years) and 2.0 for geriatric (> or = 60 years) BL. Cross-sectional age-specific rates showed 2 separate peaks among males and females, near ages 10 and 75 years, and a 3rd peak near age 40 years among males. The tri/bimodal incidence pattern was present in sensitivity analyses excluding registries with many HIV/AIDS cases and in period-specific, cohort-specific analyses. To our knowledge, tri/bimodal incidence patterns have not previously been reported for BL. Trimodal/bimodal BL suggests heterogeneity in etiology or biology of BL diagnosed at different ages in males and females.

Clinical aspects and therapy of sporadic burkitt lymphoma

Burkitt’s lymphoma is a highly aggressive mature B-cell neoplasm consisting of endemic, sporadic, and immunodeficiency-associated variants, sharing many morphologic and immunophenotypic features. It is characterized by a high proliferation rate and propensity for extranodal sites such as gastrointestinal tract and reproductive organs. Brief-duration, high-intensity chemotherapy regimens including aggressive central nervous system prophylaxis have had remarkable success in the treatment of this disease in the sporadic form, with very high complete remission rate and overall survival in adults. Although Burkitt’s lymphoma is extremely chemosensitive, biologically targeted therapies should be developed, because current treatment options are suboptimal for patients with poor prognostic features or with relapsed disease.

The extent of genetic diversity of Epstein-Barr virus and its geographic and disease patterns: a need for reappraisal

Epstein-Barr virus (EBV) is a ubiquitous, gamma-1 lymphotrophic virus etiologically linked to nasopharyngeal carcinoma (NPC), endemic to Southern China, and Burkitt lymphoma (BL), endemic to equatorial Africa, both of which are rare elsewhere in the world. Why EBV is associated with different malignancies in different geographic regions remains puzzling and may be related to EBV genotypic variability through specific disease and geographic associations. We review the literature on sequence variation in EBV genes, focusing on LMP-1, EBNA-1, and BZLF-1 and their distribution by geography and disease. Given the limitations of current studies, definitive conclusions regarding the link between EBV genotypes, disease and geography are not possible. We suggest that the true extent of EBV diversity is likely to be greater than is currently recognized. Additional studies conducted in carefully selected populations, that are sufficiently powered to provide robust estimates, and that utilize testing approaches that permit full characterization of viral diversity are needed to further our understanding of patterns of EBV genetic variation and their association with malignancies in different regions.